kennedy



1951 J. E. KENNEDY 2,563,471

CEMENT PLANT AND METHOD OF OPERATION:-

Filed Feb. 16, 1946 JOSEPH E'- KE'NNEDY wghmm ATTORNEYS Aug. 7, 1951 J. E. KENNEDY CEMENT PLANT AND METHOD OF OPERATION 2 Sheets-$heet 2 Filed Feb. 16, l946 w M Wm E @W E ATTORNEYS Patented Aug. 7, 1951 CEMENT PLANT AND-METHOD F ommn rron Joseph Elliott Kennedy, New York, N. 1'. Application February '16, 1946-, Serial No. 648,161

3 Claims. 1

My inventionrelates to improvementsin ce.;--

ment plants and; thelrmethod of; operation, and

more particularly: to. an improved plant or system, and to a process of producingcement inithe improved plant.

One of the problems involved in thevoperation of cement plants ofthe present type is the-main tenance of the equipmenttunder thesevere. operating conditions in the presence of corrosive and erosive materialshandled. Screwuconveyors, for. example, used. for handling various materials in the plant, last a relatively short time and are. often broken and out of order. Furthermore, critical parts of such conveyors must be replaced at frequent intervals becausegoi" the; excessive wear. Elevators,. such as. bucket elevators are almost equally: expensive and difilcult to maintain. Furthermore, such large quantities of ma-= terials' are handled in cement plants that the cost of equipment often prohibits the building ofthe plant, or at least increases the cost of production to such an extent that it may be im-possible to operate in a competitive market.v

According to-v the features of my, invention, 1. have discovered. that a cement plant can bebuilt and operated successfully and at relatively low cost by entirely eleminating screw conveyors and mechanical elevators; The original cost: and installation ofsuch equipment is highbecauseoi the preciseness and accuracy. with which the.

equipment must be made and installed. Fur.- thermore, as stated above the lifeoif such equipment isrelatively short. Bymaking use or. the features of my invention cram ableto eliminate some of the mostexpensive itemsin themandfacture of cement.

According to my invention: I provide a cement plant in which: the; raw materials are supplied to suitable storage areas by means. of. belt C011: veyors, and thereafter: I handle substantially all materials by means: or. one or. more overhead cranes which operate clamshells for picking up the material and-for-dumping it: in theadesi'red location I have found that a crane can. be utilized for supplying: raw materials to the processingequipment andatthe same timeemployed for removing: the cooled; clinker to. the grinding equipment where the finished product is produced. In: certain. instances, a single'crane, as for example, in. a: wet type process, is used for moving clinker in one direction and for takinc coal to the-pulverizer for: the kiln while; moving in. the. opposite: direction.

Theimprovedcementplant of my inventionine eludes astorage for: coal, a storage for: raw ma."-

terials, a storage for clinker,

akiln for receiving the-mixto be'calcined, and as an important ieaeture a special systemior cooling the clinker from the kiln and atithe same time preheating air used for firing the kiln, whichispreferably fired with: pulverized coal.

The improved plant. oixthe present invention,

as .well as its mode of. operation, includes other.

features which will be described in detail hereine after in connection with theaccompanying draw-.- ings forming a part of this application.

In the drawings, Figs. 1A. and: 1B are diagram mati'e plan views which when placed end to; end show the cement plant on ,acvery small scale with. portions broken away to simplify the showing.

Figs: 2A. and 2131v are respectively elevational views which when placed. end to end show the portions of the samezplant shown' in Figs.- 1A and 1B, the equipment beinashown diagrammatically on a. very small. scale.

Referring to. Fig.- 1A of: the. drawings, the coal to be .used. in the. cement plant is delivered from a convenient. source such as a railroad siding bya belt conveyor: I0 to a. crusher l2 from which itisdelivered bya belt conveyor l4 tov a ground storage Hi for crushed coal.: Provision, may be made. for; storing the coat: up to fliteen feet; deep so;that. a. considerable quantity may be accumu lated in. thisstoragealor use. over a particular season or some particular time when it might be inconvenient to. obtain coal deliveries. From the ground storage 5,. the coal. is. delivered. by a beltconveyor I" to astorage. bin 20,, below a track-way 2 2, on which-cranesru-and 26' operate. The storage bin 20 as Well as the track-way 22 preferably comprisesa part of a suitably long and relatively large building for covered: storage which is divided into storage bins in themanner described hereinafter.

The stone to be used'iin the manufacture of cement, according to: the present invention, is delivered at the right of the plant and fed to a primary crusher,v such as a gyratory crusher: 2-8=, by means of. a. steam-shovellor other. suitable or convenient means, the crusher. being located be lowgrourid level, as-indicated in Fig. 2A. The stone crushed by the crusher 28 is moved" by means of an inclined belt conveyor 3|) ontoa vibrating screen 32. The material: which fails to' gor through: the screen, is: passed into a secondr ary crusher atfrom which the crushed material is moved: bymeans of. a belt conveyor 36 back along: the belt conveyor. 30: l and. dumped thereon so that it is recycled to the: vibrating screen 32 this means aseparate bin: for the secondary 3 crusher is eliminated, and means is provided for preventing anything which is not finer than onehalf inch being sent to the bedding system or the ground storage.

All of the finished crushed stone delivered through the screen 32 passes through a chute onto upwardly-inclined belt conveyor 38 which delivers the crushed stone onto a distributing belt conveyor48, over-a ground storage or bedding storage 42. 'The conveyor 48 may include a traveling automatic reversible tripper 43 for dis tributing the product from any section of a quarry from one end of the beddingsystem to the other. When the separate products from all sec-,- tions of a quarry are uniformly bedded in this way and all sections of the pile aredrawn from and supplied to the process, a perfect mix is obtained for making a high-grade cement.

Beneath the bedding storage 42 is provided areclaiming belt conveyor 44 which is preferably usedin connection withdisc feeders 45 of a well-known construction and distributed along the bedding system 42. These feeders 45, which receive stone throughopenings in the bedding fioor, are driven at the same rate and all are arranged to feed the same quantityof stone onto the conveyor belt 44, thus giving an equalized cut or sample from all places in the quarry. The crushed stone on the belt 44 is carried up an incline and deposited onto a substantially horizontal belt conveyor 46 which carries the crushed stone to the stone storage bin 48 which is under the crane-way. The crane 24 may be used for distributing the crushed stone in the storage bin 48. I

A shale storage bin 58 is provided at the right end'of the building adjacent the stone storage 48. The shale for this storage may be brought into the plant through thecrushers 28and 34, delivered to a portion of the ground storage by the conveyor 48, and then delivered to the storage-58 from the conveyor 46. In a similar way gypsum for use in the plant and which is stored in a bin 52 between the stone storage bin 48 and the coal storage bin 28, is also brought in through the crushers 28 and 34 and dumped into the gypsumbin from the conveyor 46. A tripper of known construction, not shown, may be used for dumping the difierent products from the conveyor 46 into the respective bins. The foregoing procedure for handling the shale and gypsum for the plant eliminates a separate crushing plant for the shale and gypsum. It is an easy matter with the apparatus disclosed, to crush enough gypsum in a few hours in the crushers 28 and 34 to last for months. The same is true for the shale used in the cement process.

The cement manufacturing process of the present invention is illustrated as a wet process, and accordingly shale is delivered by a. clam shell 55 of the crane 24 to a feed bin 54 while the. clam shell also supplies stone to a feed bin 56. These materials, as shown in Figs. 1A and 2A, are fed at a regulated rate into a wet grinding tube mill 58'which delivers the ground'product to four cone classifiers 68 for classifying the product. The overflow from the classifiers- 68 with the finished material is delivered through a'- line 62to a set' tling tank'64 of the thickener type (Fig. 1B). The oversized product from the cone classifiers 68 is returned to the mill 58 through a line 66, for regrinding. The slurry from the large tank 64 is pumped into'slurry tanks 68 which deliver slurry to a tank 18 under the front end ofa rotary kiln 12. The tank 18 under the kiln will i more is pumped than is required for giving the proper feedtothe kiln .12; 1

The cement kiln 12 shownin Figs. 13 and 2B, is a relatively long rotary kiln which is fired by aburner 16 and which is provided with an exhausterjw'and a stack 88. The kiln i2 is shown as being fired with pulverized coal produced in a tube mill 82 to which coal is supplied from a hopper 84 which is kept filled with coal from the ;bin 28 by means of the overhead crane 26 and a clamshell 85. The tube mill is exhausted by means of a fan 86 which draws air and pulverized coal from the mill 82 up into a separator 88, from which thecoarse coal particles are returned to the mill. The stream of pulverized coal and air from the exhauster fan 86 is delivered through a pipe 98 to the burner-I6. The kiln can be fired with oil or gas if desired. Air is supplied to the tube'mill 82 from a fan 92 (Fig.2B) which delivers air under forced draft through lines 94 to points above and below a clinker cooler grate 96. The air forced into the clinker cooler by the fan 92 is heated by contact with the clinker on the grate 96 and delivered through a conduit 98 and a branch conduit I88 to the inlet of the tube mill '82. Secondary air for-the burner 16 may be drawn from the conduit 98' through another branch line I82.

The extremely hot'clinker reaching-the end of the kiln 12, as shown in Fig. 2B, is delivered througha chute onto the cooling grate 96, which is preferably-a vibrating grate adapted to advance the clinker down against" a pivoted-door I 84. This door forms a closure for the space above the grate 96 to restrict the-fiow' of air to the outlet duct 98. As theclinker accumulates against 7 the swinging door I84, the bottom of the door swings to the rightand permits the'cooled clinker to fall onto an inclined conveyor l86-which delivers thecooledclinker to a crusher l 88-. Thecrusher I88 discharges into a pit H8 and the crushed clinker is picked up by the clam shell of the overhead crane 26'an'd delivered to a clinker stor agebin H2. I I I ;The clinker may be delivered as desiredor conyenienti to a hopper H4 either directly from the pit 1.18; or from the bin'HL'and gypsum is also supplied,=by the overhead crane; to a hopper 1 I6. These materials are fed by suitable proportional regulated feeders from'the hoppers H4 and H6, to a large dry-grinding tube mill 1 l8, in'which the. clinker and gypsum are: ground together. From the tube mill the" cement dust ispassed to a cyclone separator I28 inan-airi stream induced by anexhauster I22 (Fig.--1B)t. The oversize material "from the separatorlZUris returned to the feedJend-of the mill ll8,iwhile;theifinishedma terial will be conveyed by. an automaticand continuously-operating air lift mechanism, not shown, through a line l24to cement storage silos of the usual construction, not shown.

-In5some instances, itsmaybeipossi ble to carry out Fall. of the handling operations along the crane-way 22 by the use of -a single crane, such as the crane. 24'. However, two cranes are preferalbly employed, one of which may beutilized almostexclusively in the 'moving'of coal from the bin:- 28 vto the hopper-.84 land the delivery of clinker from the pit l in either to the'clinker storage 1- or to the hopper H4. The, delivery.

orgypsum to the hopper H6 may berather infre-v quent, butthe crane 26 will be ableto. cross the. coal bin 20 and pick upthenecessary yps mv from the bin 52 without inconvenience. The stone storage andshale storage in a plant of this type are relatively large, particularly the sto storage, so that the crane 24 may be pretty w ll occupied in supplying the shale and stone to th hoppers 54 and 56., If necessary, howev r, it; wi l.

The; provision of an overlapping belt conveyo system and crane-way system-in a straightaway arrangement of the equipment, tog ther with the other arrangements shown in the drawings, provides a unique system for the handling of the materials in a cement plant in, an economical manner. The straight line handle of the materials, together with the overlapping crane-way and belt. conveyors eliminates considerable ground space for the plant as well as eliminating theuse of separate crushers for handling gypsum and shale. 1

While the cement plant of the present invention, as well as its operation, has been described in connection with the use of shale, ypsum, and stone, the plant may be utilized in substantially the same manner if the materials processed are stone, gypsum and clay, although a wash mill may have to be provided for washing the clay before delivery to the wet grinding tube mill 58.

From the foregoing; description, it will be understood that some changes might be made in the equipment used in thevarious steps without materially changing the general arrangement ofthe plant and its operation. Such changes are contemplated as coming within the scope of the appended claims.

What I claim as new is:

1. In a cement plant having means for handling raw materials and clinker without the use of screw conveyors or mechanical elevators, the improvement which comprises a plant layout including, in succession and in a substantially straight line, a raw materials crusher, a raw materials bedding storage means, a materials storage building long in the direction of the straight line layout and having storage bins arranged successively in the line of the layout, and a rotary kiln for producing cement clinker from the raw materials having charge and discharge ends, said kiln being arranged with its discharge end adjacent to the end of the storage building opposite the bedding storage, a belt conveyor extending from the raw materials crusher to and along the bedding storage means for conveying crushed raw materials thereonto, a belt conveyor system having portions extending respectively along the raw materials bedding storage means and along a plurality of the bins in the storage building, means for depositing raw material from the raw materials bedding storage means onto said portion of the belt conveyor system extending therealong, means for discharging raw materials from the portion of the belt conveyor system extending along the storage building into selected ones of said plurality of storage bins therein, a craneway extending the length of the storage building above the storage bins, a crane and clamshell operablei along said craneway overthe storage; bins: of the, building for, the transfer of materials: a raw materials grinding mill; of the storage building. hoppers. 1 positioned for receivingraw materials handled, by the crane and clamshell and for delivering stored therein, adjacent one side raw materials to the raw materials grinding mill, means for conveying raw materials from the grinding mill to the chargingrend of the kiln. a.

cement clinker receiving pitin the end portion of: the storage building end, of the kiln, means cooler for transferring cement clinkerfrom the discharge end of the he storage building, anda cement clinkerstoli age bin in the building adjacenttothe clinker: clinker discharged into. the:

pit whereby cement pit may be readily the clinker storage shell.

2. In a cement plant. havingmeans for handltransferred therefrom into,

ing raw materials and clinker without the use successively in the line of thelayout, and a rotary cement clinker from the raw kiln for producing materials having charge and discharge ends, said kiln being arranged with its discharge end adja.--

cent to the end of the storage building opposite the bedding storage, a belt conveyor extending from the raw materials crusher to. andalong: the: bedding storage means for conveying crushed raw materials thereonto over the length of the; bedding storage, a belt conveyor system having portions extending respectively along the raw;

materials bedding storage means and. along a plurality of the bins in the storage building, means at spaced points along the bedding storage for simultaneously feeding raw material from the raw materials bedding storage means onto said portion of the belt conveyor system extending therealong, means for discharging raw materials from the portion of the belt conveyor system extending along the storage building into selected ones of said plurality of storage bins therein, a craneway extending the length of the storage building above the storage bins, a crane and clamshell operable along said craneway over the storage bins of the building for the transfer of materials stored therein, a raw materials grinding mill adjacent one side of the storage building, hoppers positioned for receiving raw materials handled by the crane and clamshell and for delivering raw materials to the raw materials grinding mill, means for conveying raw materials from the grinding mill to the charging end of the kiln, a cement clinker receiving pit in the end portion of the storage building adjacent to the discharge end of the kiln, means including a cement clinker cooler for transferring cement clinker from the discharge end of the kiln into the clinker pit in the storage building, and a cement clinker storage bin ln the building adjacent to the clinker pit whereby cement clinker discharged into the pit may be readily transferred therefrom into tlhe clinker storage bin by the crane and clams ell.

3. In a cement plant having means for handladjacent to the discharge. including a, cement clinker;

kiln into the clinker pitin,

bin by the crane and clamps-- ingraw materials and clinker without theus'e of screw conveyors ormechanical elevators, the

improvement which comprises a plant layout inage building long in the direction of the straight line layout and having storage bins arranged successively in the line of .the layout, and a rotary kiln for producing cement clinker from the raw materials having charge and discharge ends, said kiln being arranged with its discharge end adjacent to the'end of "the storage building opposite the bedding storage, a belt conveyor extending from the raw materials crusher to and along the bedding storage means for conveying crushed raw materials thereonto, a belt conveyor system having portions extending respectively along the raw materials bedding storage means and along a plurality of the bins in the storage building, means for depositing raw material from the raw materials bedding storage means onto said portion of the belt conveyor system'extending therealong, means for discharging raw materials from the portion of the belt conveyor system extending along the storage building into selected ones of said plurality of storage bins therein, a craneway extending the length of the storage building above the storage-bins, a crane and clamshell operable along said craneway over the storage bins 'of the building for the transfer of materials stored therein, a raw materials grindin mill adjacent one side of the storage building, hoppers positioned for receiving raw materials handled by the crane and clamshell and for delivering rawmaterials'to the raw materials grinding mill, means for conveying raw materials from the grinding mill to the charging end of the kiln, a cement clinker receiving pit in the end portion of the storage building adjacent to the discharge end of the kiln, means including a cement clinker cooler for transferring cement clinker from the discharge end of thekiln into the'clinker 'pit in: the storage building, a cement clinker storage. bin.

in the building adjacent to the clinker pit, a coal storagebin in the building adjacent to the clinker, storage bin, and a coal hopper at the end portion of the storage building adjacent to the discharge end of the kiln for delivering coal for firing the kiln, said coal hopper being accessible to said crane and clamshell, whereby the crane and clamshell may deliver coal from the coal bin to the coal hopper when moving toward the kiln and transfer clinker from the clinker pit to the.

clinker storage bin when moving in the opposite direction.

REFERENCES CITED The'follow ing references'are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Pages 86, 89 of The Rotary Kiln, published 1902 by A. M. S., Armstrong Harrison Building,

Philadelphia.

Pages 25 to 28 of The Chemistry of Cement and Concrete, by Lea and Desch.

Page 451 of Cement, Limes, and Plasters, by Eckel, 3rd edition.

JOSEPH ELLIOTT KENNEDY. 

